This is probably beyond elementary to the electronics experts here but:
I heard a sustained tone in my latest recording with a pair of mics I have been using forever--an ancient Church Audio model with Primo capsules if I remember correctly. Tested the mics and sure enough it's from them: a hmmmmmm from the left mic and a HMMMMMMMMMMMMM from the right, especially if I touch it. Steady and sustained, probably 60hz.
It's not in the mic jack, line-in or battery box, thank goodness.
Would this be the capsules announcing their retirement? (If so, they deserve a gold watch and a pension for faithful service.)
Or would it be in the plug? Is it worthwhile to get that rewired?
Thanks for any advice.